SAN DIEGO - A spell of cool and wet spring conditions that arrived in the San Diego area early this week continued Friday, dousing the county with mild rains in advance of a storm system expected to bring heavier downpours and a chance of thunderstorms over the weekend.

Areas that received some of the highest precipitation amounts over the 72-hour period ending at 5 p.m., according to the National Weather Service, included Mount Palomar, with 0.86 of an inch; Lake Cuyamaca, 0.72; Mount Laguna, 0.68; Alpine, 0.66; Descanso, 0.61; Santa Ysabel, 0.57; Pine Hills, 0.56; and Otay Mountain. 0.5.

The showers were expected to weaken overnight, but rainfall over the weekend will be more intense, delivering moisture totals ranging from three-quarters of an inch along the coast to 1.75 inches in the East County highlands, forecasters said.

The series of storms will continue in weaker fashion through most of next week, the NWS advised.